In optical systems using fiber optics for transmitting signals by light energy, it is often necessary to couple two fibers end-to-end for the signal transmission path. The optical fibers are of very small diameter and are of fragile construction. Typically, a fiber optic cable comprises an optical fiber covered by a jacket of plastic material for protecting the fiber from damage due to handling during installation and exposure in its operating environment. A typical single filament cable comprises a glass fiber having a diameter of a few thousands of an inch and a protective jacket having a diameter a few hundreds of an inch. In order to facilitate repeated connection and disconnection of one or more pairs of fibers it is desirable to utilize separable connectors having single or multiple terminal pairs, such as the connectors commonly used in the electronic industry.
A connector for optical fiber cables must provide for accurate alignment of the pairs of fibers being joined and provide support for the cable jacket in order to relieve the fiber itself from stress. The connector must be provided with terminals for the pairs of fibers being joined which are capable of repeated connection and disconnection and which are of simple and low cost construction.
In the prior art, connectors for fiber optic cables have been disclosed which utilize pin and socket type terminals. Such an arrangement is described in U.S. Pat. No. 4,140,366 granted to Makuch et al. In the connector of this patent, each fiber or bundle of fibers is provided with a special termination which has an end flush with the end of the fiber or fiber bundle. The termination for one fiber or fiber bundle is disposed within a socket on one connector member and the termination for the other fiber or fiber bundle is disposed within a tubular pin which is mated with the socket to juxtapose the terminations end-to-end.
The prior art also discloses single filament optical fiber cables coupled in end-to-end relationship by attaching a ferrule to the end of the single fiber and mechanically aligning and connecting the ferrules together. Typically, the fiber is encased in the ferrule so that the end of the fiber is flush with the end of the ferrule. Two fibers are coupled by placing the respective ferrules in end-to-end abutting relationship. This type of connector is disclosed in U.S. Pat. No. 4,087,158 granted to Lewis et al. and U.S. Pat. No. 4,090,778 granted to Phillips et al.
Also, in the prior art, attempts have been made to provide a fiber optic cable connector in which the fibers are aligned by matching terminations each of which supports a respective cable with the free end of the fiber extending therefrom. In connectors of this type, the free ends of the corresponding pairs of optical fibers are disposed in a V-groove on one of the terminations and a holding means on the other termination bears against the fibers to hold them in alignment in the V-groove. This kind of arrangement is disclosed in U.S. Pat. No. 3,885,859 granted to Dalgleish et al. and in U.S. Pat. No. 4,088,386 granted to Hawk.
A general object of this invention is to provide a fiber optic cable connector of the pin and socket type which overcomes certain disadvantages of the prior art.